Mission Timeline:
Mars Odyssey Flight Phases and Significant Dates

To use the Mars Odyssey Gamma-Ray Spectrometer data effectively,
it is essential to be familiar with the flight phases of the
spacecraft and important mission milestones. The three main phases
of the mission are:

Aerobraking Phase of the Odyssey mission, where the spacecraft
uses the thin outer atmosphere of Mars to slow its speed and
achieve a stable orbit.

Feb. 19, 2002
through the present

Primary Mapping Phase of the GRS mission.

Important Primary Mapping Phase Dates

It is important to note that from February 19, 2002
through June 1, 2002, the GRS
was in Stowed Mapping configuration, with the Gamma Subsystem
measuring background signals from the spacecraft before the
GS boom was deployed.

Beginning June 5, 2002, and continuing through August, 2004,
the spacecraft entered the Deployed Mapping phase, after the
Gamma Subsystem boom was fully deployed, separating the GS
from the background signals of the spacecraft.

Detailed Listing of Important Odyssey GRS Dates

The GRS Data Node querying software does not include information
in output data about which phase of the mission the data was collected
in. That information must be determined by the user according to
the dates listed by the mission timeline, below:

Event(s)

Date(s)

Description or Information

Launch

April 7, 2001

Launch of the Mars 2001 Odyssey spacecraft and beginning of the Cruise phase.

Cruise Phase Begins

April 7, 2001

The cruise phase of the mission is the journey of the spacecraft to Mars,
before orbital insertion and aerobraking.

CEB Powered On

April 25, 2001

The Central Electronics Box (CEB) is powered on for the first time in
flight, during the Cruise Phase.

GS, NS, and HEND are powered on

May 2, 2001

The Gamma Subsystem (GS), the Neutron Spectrometer (NS), and the
High Energy Neutron Detector (HEND) are powered on for the
first time in flight, for testing and calibration en route to
Mars.

GS Data collected off and on

May 2, 2001
through
Sept. 4, 2001

Gamma Subsystem data is collected off and on during this
period for testing and calibration of instruments.

All instruments on Odyssey are shut down for the Mars Orbit Insertion
on September 24, 2001.

Cruise Phase Ends

Oct. 23, 2001

The cruise phase of the mission is the journey of the spacecraft to Mars,
before orbital insertion and aerobraking.

Aerobraking Maneuvers Begin

Oct. 24, 2001

During the aerobraking phase, the spacecraft achieves a stable orbit around Mars.

Data Collection (Short)

Oct. 24, 2001
to
Oct. 26, 2001

GS, NS, HEND data collected for 2 days

GRS Shut Down

Oct. 26, 2001
through
Nov. 16, 2001

All Gamma Ray Spectrometer Instruments shut down when
the spacecraft was put into safe mode.

Data Collection

Nov. 16, 2001
through
Dec. 19, 2001

Science data was collected off and on during this period.

GRS Shut Down

Dec. 19, 2001
through
Jan. 14, 2001

Science data was collected off and on during this period.

Data Collection

Jan. 14, 2002
through
Feb. 18, 2002

Science data was collected off and on during this period,
with a short data outage on February 15, 2002. There may
be other data gaps during this period due to missing
telemetry.

Aerobraking Maneuvers End

February 18, 2002

During the aerobraking phase, the spacecraft achieved a stable orbit around Mars.

Primary Mapping Phase Begins

Feb. 19, 2002

Primary Mapping phase of the mission began on Feb. 19, 2002,
and is expected to continue until August, 2004.

Stowed Mapping

Feb. 19, 2002
through
June 1, 2002

By this time the spacecraft has achieved a mapping orbit, and during
the Stowed Mapping period the 6-meter Gamma Subsystem boom is not deployed,
but still in "stowed" configuration. Data collection during this
time includes the background hydrogen signal from the spacecraft.

During the stowed mapping period, two anneals were performed on
the gamma detector. During these dates no science data was
collected:

March 8, 2002 through March 22, 2002
and
May 6, 2002 through May 20, 2002.

Deployment of GS Boom

June 1, 2002
through
June 4, 2002

The GRS was shut down on June 1, 2002 to prepare for the Gamma Subsystem
Boom deployment, which was performed on June 4, 2002.

Deployed Mapping Phase

June 5, 2002
through
August, 2004

The Deployed Mapping Phase is the primary scientific data collection phase
of the mission.